Can Animals Feel Jealousy?
Animals are more emotionally complex than we think, but are they capable of feeling jealousy? A new comprehensive analysis has suggested that they don’t really get too worked up over unfairness the way that humans do.
The findings challenge the idea that other species display “inequity aversion,” a negative response to receiving less than others.
Researchers examined data from 23 studies that cover more than 60,430 observations across 18 different species, including cockatoos and chimpanzees.
They focused their analysis on experiments in which animals were given the opportunity to accept or reject rewards that were offered to them.
Investigations into animal fairness and jealousy started in 2003 with the study of capuchin monkeys. In an experiment conducted by Frans de Waal, two monkeys performed the same task for rewards. They willingly completed their tasks when they both received cucumber slices.
But when one monkey received a grape instead of a cucumber slice, the other monkey refused the cucumber slice and even threw it at the researcher. Similar studies with dogs, mice, and corvids resulted in similar responses.
However, the researchers of the new study have suggested that this interpretation may not be wholly accurate and that human characteristics are being attributed to animal behavior.
In humans, our sense of fairness when it comes to distributing resources seems to be essential to the foundation of our society. It allowed our ancestors to share food, build shelters, and develop complex social structures.
Earlier studies on animal fairness and jealousy were limited by sample sizes that were too small and difficulties with replication.
Sign up for Chip Chick’s newsletter and get stories like this delivered to your inbox.
So, the team wanted to investigate further. They combed through 20 years of experiments that tested animals’ responses to unequal rewards.
Across all the species, there was no strong evidence that animals reject rewards because of unfair treatment. Sometimes, they refused lesser rewards after seeing better ones offered to others, but the behavior was likely due to disappointment, not something as complex as a sense of fairness.
“We can’t make the claim that animals experience jealousy based on this data,” said Oded Ritov, the lead author of the study and a fourth-year Ph.D. candidate in UC Berkeley’s Department of Psychology.
“If there is an effect, it’s very weak and might show up in very specific settings. But it’s nothing like what we see in humans in terms of our deep-seated sense of fairness.”
It appears that the ability to identify and object to unfair treatment is unique to humans. The researchers believe that the act of the monkey throwing the cucumber at the researcher was driven by disappointment.
It can be difficult to distinguish between disappointment and fairness in animal behavior because humans are prone to projecting their own qualities onto other animals.
While animals do demonstrate complex emotions, they do not exhibit an understanding of equity and justice. Those traits are special to humans.
The findings were published in Proceedings of the Royal Society B.
More About:Animals
Read This Next
